So,,
for all (including me) of you who have asked and searched this site for information on the weber 38/38 on a truck.
I have a 1982 D150 (slant, needless to say) NP435 transmission, 3.5 rear, Chevy HEI, 2.5 inch exhaust. The rest is stock.

It had a holley 1920 single barrel carb on it. It would get about 15 MPG mixed city and highway. I once got 21 MPG highway only, going 50 to 55 MPH.
Top speed: 70 MPH,, barely!!

Well, the carb finally fell apart on me, and it came time to replace it. I went with a Weber38 jeep kit from redline. Installed it on an Offenhauser 4 barrel aluminum intake.
( now have a super 6 intake,, .. Should I switch out the Offenhauser?)
Here are my results.
I get 17 MPG mixed (highway and city)
top speed: I don't know, It keeps going!!!
Acceleration is great, way better than before.
I will try and improve on the MPG, I bet I can get close to 20 MPG... I'm excited to try...

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Slant power!!!
At least I try...

The Offy runners are about the same size as a factory intake and it is lightweight aluminum. I'd stay with the Offy.

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“Buy the ticket, take the ride.”
― Hunter S. Thompson

This is what I was going to say. If it's running fine just leave it alone. I've wondered how that carburetor would behave in a truck. Waiting to hear your gas mileage report.

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If it was easy, everybody would be doing it.